<template>
  <div class="home-page">

  <div class="banner">
    <div class="container">
      <h1 class="logo-font">conduit</h1>
      <p>A place to share your knowledge.</p>
    </div>
  </div>

  <div class="container page">
    <div class="row">

      <div class="col-md-9">
        <div class="feed-toggle">
          <ul class="nav nav-pills outline-active">
            <li v-if="user" class="nav-item">
              <nuxt-link
                  class="nav-link"
                  :class="{
                    active: tab === 'your_feed'
                  }"
                  exact
                  :to="{
                    path: '/',
                    query: {
                      tab: 'your_feed'
                    }
                  }"
                >Your Feed</nuxt-link>
            </li>
            <li class="nav-item">
              <nuxt-link
                  class="nav-link"
                  :class="{
                    active: tab === 'global_feed'
                  }"
                  exact
                  :to="{
                    path: '/'
                  }"
                >Global Feed</nuxt-link>
            </li>
            <li v-if="tag" class="nav-item">
              <nuxt-link
                  class="nav-link"
                  :class="{
                    active: tab === 'tag'
                  }"
                  exact
                  :to="{
                    name: 'home',
                    query: {
                      tab: 'tag',
                      tag: tag
                    }
                  }"
                ># {{ tag }}</nuxt-link>
            </li>
          </ul>
        </div>

        <div
         class="article-preview"
         v-for="article in articles"
         :key="article.slug"
         >
          <div class="article-meta">
            <nuxt-link :to="{
              name: 'profile',
              params: {
                username: article.author.username
              }
            }">
              <img :src="article.author.image" />
            </nuxt-link>
            <div class="info">
              <nuxt-link class="author" :to="{
                  name: 'profile',
                  params: {
                    username: article.author.username
                  }
                }">{{article.author.username}}</nuxt-link>
              <span class="date">{{ article.createdAt | date('MMM DD, YYYY') }}</span>
            </div>
            <button class="btn btn-outline-primary btn-sm pull-xs-right"
              @click="onFavorite(article)"
              :class="{
                active: article.favorited
              }">
              <i class="ion-heart"></i> {{article.favoritesCount}}
            </button>
          </div>
          <nuxt-link :to="{
                name: 'article',
                params: {
                  slug: article.slug
                }
              }" class="preview-link">
            <h1>{{ article.title }}</h1>
            <p>{{ article.description }}</p>
            <span>Read more...</span>
          </nuxt-link>
        </div>

      </div>

      <!-- 分页列表 -->
          <nav>
            <ul class="pagination">
              <li
                class="page-item"
                :class="{
                  active: item === page
                }"
                v-for="item in totalPage"
                :key="item"
              >
                <nuxt-link
                  class="page-link"
                  :to="{
                    path: '/',
                    query: {
                      page: item,
                      tag: $route.query.tag,
                      tab: tab
                    }
                  }"
                >{{ item }}</nuxt-link>
              </li>
            </ul>
          </nav>
          <!-- /分页列表 -->

      <div class="col-md-3">
        <div class="sidebar">
          <p>Popular Tags</p>

          <div class="tag-list">
            <nuxt-link
             :to="{
               path: '/',
               query: {
                 tab: 'tag',
                 tag: item
               }
             }"
             class="tag-pill tag-default"
             v-for="item in tags"
             :key="item"
             >{{item}}</nuxt-link>
          </div>
        </div>
      </div>

    </div>
  </div>

</div>
</template>

<script>
import {
  getArticles,
  getFeedArticles,
  addFavorite,
  deleteFavorite
} from '@/api/article'
import { getTags } from '@/api/tag'
import { mapState } from 'vuex'
export default {
    name: 'homeindex',
    async asyncData({ query, store }) {
      const page = Number.parseInt(query.page || 1)
      const limit = 20
      const { tag } = query
      const tab = query.tab || 'global_feed'
      const loadArticles = store.state.user && tab === 'global_feed' ?
        getArticles : getFeedArticles
      const [articleRes, tagRes] = await Promise.all([
        loadArticles({
          limit,
          offset: (page - 1) * limit,
          tag
        }),
        getTags(),
      ])
      const { articles, articlesCount } = articleRes.data
      const { tags } = tagRes.data
      articles.forEach(article => article.favoriteDisabled = false)
      return {
        articles,
        articlesCount,
        limit, // 每页大小
        page, // 页码
        tags,
        tag,
        tab
      }
    },
    watchQuery: ['page', 'tag', 'tab'],
    computed: {
      ...mapState(['user']),
      totalPage () {
        return Math.ceil(this.articlesCount / this.limit)
      }
    },
    methods: {
      async onFavorite (article) {
        article.favoriteDisabled = true
        if (article.favorited) {
          // 取消点赞
          await deleteFavorite(article.slug)
          article.favorited = false
          article.favoritesCount += -1
        } else {
          // 添加点赞
          await addFavorite(article.slug)
          article.favorited = true
          article.favoritesCount += 1
        }
        article.favoriteDisabled = false
      }
    }
}
</script>

<style>

</style>